The new findings illustrate how environmental impacts can
reverberate through the food web.

“Ninety-nine percent of food that pandas eat in the wild is
bamboo,” said Jack Liu, an ecologist at Michigan State University
in East Lansing. “If there’s no bamboo, then pandas can’t
survive.”

“I think probably there is hope, but only if we take active
measures at once,” he added. “If we don’t, then probably not. It
really depends on what we will do.”

With fewer than 1,600 individuals left living in the wild, giant
pandas are one of the most endangered species in the world. But
most panda-conservation research has focused on human impacts,
said Liu, who has been studying pandas and their habitats for 17
years.

To find out what kind of influence climate change might have on
the adorable fur-balls, he and colleagues zeroed in on the
Qinling Mountains, which provides about a quarter of available
habitat for wild pandas.

Using a wide range of climate models, the researchers projected
likely changes in three main species of bamboo, which make up
more than 90 percent of bamboo in the region. Bamboo plants are
highly sensitive to temperature changes.

Under every scenario, the researchers report today in the journal
Nature Climate Change, dramatic declines in bamboo would likely
spell big trouble for pandas. Estimates for how much suitable
habitat would disappear ranged from 80 to 100 percent, depending
on the climate scenario used.

Despite the relatively large amount of panda habitat currently
available in the Qinling Mountains, the region is isolated from
other suitable habitats. That means that if their food source
were to disappear, pandas that live there would have nowhere else
to go. The region’s remoteness also makes it unlikely that new
species of bamboo would be able to get their seeds there.

The results suggest that conservationists must consider climate
change as well as human impacts when planning how best to protect
pandas, Liu said. One possible solution would be to cultivate and
plant heat-tolerant bamboo in the region.

But even if researchers find bamboo that will continue to grow
with warming, said Stanford ecologist Terry Root, they’d also
need to ensure that pandas could get sufficient nutrients from
those plants. And that’s not necessarily a sure thing.

Because pandas are so charismatic and popular, Root added, they
provide a poignant example of scenarios happening to all sorts of
species all over the world.

“Most biologists think we’re standing on the edge of a mass
extinction event,” she said. “If pandas can bring attention to
that, it’s absolutely fantastic. This is a horrible thing to say,
but I think this is a wonderful study because what it’s doing is
showing us how we need to actually understand what we’re doing to
the climate, because we’re not just doing it to the climate.”

Again and again, ecologists are documenting how changes to one
species create domino effects that resonate through the rest of
the ecosystem in unexpected ways.

"It's going on all over the place, we just haven’t noticed it,"
Root said. "Actually noticing it in an iconic species like the
panda is super unfortunate, but maybe it will get people to
understand what’s going on. It's a wake-up call."